Online Inertia Estimation of Droop Control-Based Grid-Forming Inverters in Islanded Microgrid
Saeid Pashazadeh, Zahra Dehghani Arani, Amir Khorsandi, Hamed Nafisi. Gevork B. Gharehpetian Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran 2026-06-27

Abstract

Inertia estimation of the droop control-based grid-forming (GFM) inverters has not been performed in an islanded microgrid by using an online method with low computational cost. This paper deals with this issue by considering the relationship between the active power-angular frequency droop equation and the conventional swing equation. As a solution, a first-order differential equation in the time domain is extracted from the active power-angular frequency droop equation in the Laplace domain to estimate the inertia constant of the GFM inverter. The simulation results conducted in the MATLAB/SIMULINK environment confirm the accuracy of the proposed inertia estimation method with different angular frequency droop gains as well as under load variation conditions.

Key words: Angular Frequency Droop Gain, Grid-Forming Inverter, Inertia Estimation, Islanded Microgrid

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